WO-A 2008/058913 describes the production of flexible polyurethane foams from polyether carbonate polyols using amine-free stabilizers against thermooxidative degradation, i.e. amine-free antioxidants such as sterically hindered phenols, lactones and amine-free antioxidants which do not eliminate phenol and any desired mixtures of these compounds. The combination of amine-free and aminic antioxidants is not disclosed.
In the context of an environmentally friendly design of production processes, it is generally desirable to use CO2-based starting materials in relatively large amounts. In the production of the polyurethane foams, said foams have a propensity for thermooxidative degradation. The present invention accordingly has for its object the provision of a process for producing polyurethane foams which comprise a high proportion of polyether carbonate polyols, wherein the resulting polyurethane foams are protected against thermooxidative degradation.
Surprisingly, this object was achieved by a process for producing polyurethane foams in which the reaction of an isocyanate component B with an isocyanate-reactive component A which comprises at least one polyether carbonate polyol is effected in the presence of a nonaminic antioxidant and an aminic antioxidant.